In many mobile telecommunications systems, such as, for example, in a third generation (3G) evolved universal terrestrial radio access network (E-UTRAN) telecommunications system, a number of base stations (E-UTRAN node Bs—eNBs) are arranged to communicate with a number of user equipment (UEs). A number of channels are provided between the base stations and user equipment to support this communication. Each base station is geographically separated from the others in order to provide communications coverage over a wide area. Also, each base station is typically arranged to support a number of ‘sectors’ extending outwards from the base station location.
User equipment may establish a communications link with a base station when within its associated sector. As the user equipment roams throughout the network it will eventually leave its current sector and enter a new sector. When this happens, the current base station will need to ‘handover’ the user equipment to a base station associated with that new sector. To assist in this process, the user equipment typically continually attempts to identify further base stations with which it may establish a communications link. Likewise, the network itself may derive information from the user equipment and indicate to the user equipment details of the most likely base station to which a handover may occur. The sectors generally overlap somewhat geographically to enable communication with an existing base station to be retained until communication with a new base station can be established and a handover can occur. It can be seen that this enables user equipment to roam throughout the network, with the user equipment being handed over from base station to base station.
It will be appreciated that this arrangement helps to ensure that user equipment can reliably establish a connection and enables the user equipment to room through the network. However, a problem with the arrangement described above is that the network consumes large amounts of power.
It is desired to provide an improved arrangement which consumes less power.